Poly(oxypropylene/oxyethylene) random polyols useful in preparing flexible high resilience foam with reduced tendencies toward shrinkage and foam prepared therewith

Abstract

High resilience polyurethane foams exhibiting little or no shrinkage may be prepared from low unsaturation double metal cyanide catalyzed polyoxyalkylene polyols in amounts greater than 20 weight percent of the total polyol component, when low unsaturation poly(oxypropylene/oxyethylene) random polyols having less than 35 weight percent of an all polyoxypropylene block catalyzed by double metal cyanide catalysts and one or more external random polyoxypropylene/polyoxyethylene blocks each containing 2 weight percent or more oxyethylene moieties, and an unsaturation of less than 0.02 meq/g are employed.

What is claimed is: 
     
       1. A polyol suitable for use in a high resilience foam formulation at levels of greater than about 20 percent of the weight of a polyol component used to prepare said foam while producing a foam with little or no shrinkage, said polyol comprising a polyoxyalkylene polyol prepared at least in part in the presence of a double metal cyanide complex oxyalkylation catalyst and having an unsaturation of less than 0.02 meq/g, wherein said polyoxyalkylene polyol contains less than 35 weight percent of an all polyoxypropylene internal block prepared in the presence of said double metal cyanide complex catalyst, and wherein said polyoxyalkylene polyol has one or more random poly(oxypropylene/oxyethylene) external block(s), each of said external blocks containing minimally 2 weight percent oxyethylene moieties based on the weight of the block(s). 
     
     
       2. The polyol of claim 1 wherein said polyoxypropylene internal block constitutes less than about 20 weight percent of said polyol, and wherein at least one of said one or more external block(s) constitutes about 7 weight percent or more oxyethylene moieties based on the weight of the block. 
     
     
       3. The polyol of claim 2 wherein a most external block contains about 40 weight percent or more oxyethylene moieties based on the weight of the block. 
     
     
       4. The polyol of claim 1 wherein said polyol is end-capped with an all oxyethylene block such that the primary hydroxyl content of said polyol is greater than about 50 mol percent. 
     
     
       5. A polyol blend suitable for the preparation of shrink-free high resilience polyurethane foam, comprising one or more polyols of claim 1 in an amount of 20 weight percent or more based on the weight of said polyol blend, and up to 80 weight percent of one or more primary hydroxyl polyols. 
     
     
       6. The polyol blend of claim 5 further comprising an amount of one or more polyol polymer dispersions effective to provide a solids content of from about 2 weight percent to about 35 weight percent based on the weight of said polyol blend. 
     
     
       7. The polyol blend of claim 5 wherein said polyol(s) of claim 1 comprise greater than 50 weight percent of said polyol blend. 
     
     
       8. The polyol of claim 1 wherein at least 70 mol percent of oxyalkylene moieties of said polyoxyalkylene polyol are derived from oxyalkylation in the presence of a double metal cyanide complex catalyst.